Throughout ancient history, few outside forces have been able to threaten the Japanese mainland.
The limited level of production and military capabilities of the feudal society era made it possible for Japan, an island nation far from the mainland, to be in a safe corner. But on the other hand, Japan is also trapped in the narrowness and barrenness of isolated islands, and always wants to expand its living space, which is why Japanese people frequently use troops overseas.
As a neighbor of Japan, North Korea has always played a sad role in being invaded. However, what is less known is that North Korea also invaded the Japanese mainland, and that war was called the "Jihai Crusade".
After the beginning of the 14th century, the Goryeo Dynasty on the Korean Peninsula gradually declined, and at the same time, a large number of bankrupt samurai became pirates in Japan, across the sea. Seeing that North Korea's coastal defenses were relaxed, these Okou armed with oriental knives decided to take a desperate move, and the Wakou problem that had plagued North Korea for decades began. Through attacks on the Korean coast, the Wokou "profited" a lot, while the Goryeo army was repeatedly defeated due to decadence and corruption, and the Goryeo dynasty began to falter under internal and external troubles.
At the end of the stormy Goryeo Dynasty, the general Yi Sung-gui gradually emerged, and he fought invincible in the east and west, and established a high prestige among the people. In 1392, Yi Sung-gui overthrew the Goryeo Dynasty and established the Yi Joseon Dynasty, but at this time the problem of the Yokou that plagued Korea remained unresolved, and the Yi dynasty was determined to eliminate external troubles and eradicate the Wokou grass. After one bloody battle after another, the Wokou were severely damaged, but the North Koreans had no intention of stopping, and their next target was Tsushima Island, the Japanese mainland.
Tsushima Island is located between the Korean Peninsula and the Japanese archipelago, and although closer to Korea, it is Japanese territory. And because of its convenient geographical location, it has also become a "base camp" for harassing Japanese pirates.
Historically, every time Japan expanded to the mainland, Tsushima Island was used as a springboard, and even the Yuan Dynasty's crusade against Japan had to use Tsushima Island as a base for advance.
On June 17, 1419, Joseon general Yi Congmao led 17,000 troops on 227 warships to set out on Geoje Island, but encountered headwinds and returned to Geoje Island. On the 19th, he set out again and landed at Asama Bay on Tsushima Island the next day, where he met Japanese pirates.
In this battle, Li Congmao captured a total of 129 Japanese ships, burned 109, left 20 spares, and burned 2,000 houses and crops in the fields. After several small encounters, 104 Wakou were killed, 21 captured alive, 131 captured Chinese were rescued, and the army was stationed at Funakoshi. After several bloody battles, the old nest of the Wako on Tsushima Island has been destroyed, and the exhausted North Korean army has returned to the DPRK.
After this war, peace was restored between North Korea and Tsushima, and long-term trade between the two sides was mutually beneficial, which was the famous "Jihai Crusade" in Korean history.